The scene in the small engagement zone was truly chaotic.
When the Battle Servitors rotated their immense bodies to track the fast-moving targets, they invariably obliterated one or two friendly Combat Servitors with stray fire. Several Skitarii were wounded by the shrapnel of their exploded allies.
The Plague Marines, in turn, used the dense, intermingling ranks of the Skitarii and Combat Servitors to limit the effective fire of the Battle Servitors.
No one noticed the entry of two entirely new mechanical forms onto the periphery of the battlefield.
The matte, sand-blasted casing of the Automated Sentry-Troopers effectively absorbed ambient reflections as they moved with surprising speed and agility.
Utilizing a digital uplink, Axion controlled one of the Automated Sentry-Troopers to raise its grav-autocannon, aim it at the sky, and pull the trigger. This unique force-field weapon produced a deep, rhythmic thrumming sound when fired, akin to a taut bowstring being violently released.
"Woom! Woom! Woom!"
The unusual sound was quickly registered by both engaged factions.
The Plague Marines, seeing the completely unfamiliar mechanical constructs, showed no sign of stopping. Since these machines were not part of their own forces, they were the enemy. Destruction now or destruction later made no difference; they would be dismantled regardless. In their virally-addled minds, the Plague Marines' reasoning was sometimes as simple as that of an Ork.
The Adeptus Mechanicus personnel whose attention was drawn by the sound fell into a moment of hesitation, only to immediately resume fighting when the blood of their comrades splattered onto them.
The extreme proximity of the fighting prevented the Mauler Bolt Cannon mounted on the Triaros from firing. This was not merely due to the firing angle limitations, but also the weapon's massive destructive power.
If Morlan had forced the issue and ordered it to fire, he would be charged with the slaughter of Imperial warriors even if he miraculously returned to the Hive City. Without the aid of others, even an Enginseer could not escape the fate of being converted into a Servitor or, worse, a Penitent Engine.
Shuddering at the thought of such a gruesome end, Morlan shook his head. He would rather die on the battlefield than suffer that indignity.
As for concealment, that was impossible. Servo-skulls crisscrossed the battlefield, providing combat assistance and data transcription. Everything that transpired here was being constantly relayed back to the Hive City. The data-scribes would record it all into explicit archives.
Soon, an alert from the Battle Servitor embedded within the Triaros prompted Morlan. He had finally identified the source of the interruption that had briefly stunned the battle.
"What are these? Two armed automatons? A pattern never before encountered."
The sudden appearance of a third faction immediately excited Morlan. As he guided the Servo-skulls to examine the new, uninvited guests, the events that followed nearly caused his consciousness to seize.
Under Axion's control, the Automated Sentry-Troopers raised their neutron beam emitters. A gentle, warm yellow beam of light erupted from the muzzle, easily striking a Plague Marine who was carving through the mixed-up fighting ranks.
The Plague Marine, who had been virtually immune to standard pattern las-fire, instantly ceased all movement the moment he was hit.
"AAAAAAAHHHHH!"
A horrifying wail tore from the Plague Marine's throat. Blessed by Nurgle, he should have felt no pain, yet a strange, searing sensation overwhelmed him.
Even the combatants nearby froze due to the sheer volume of the scream.
"What has occurred?"
Binary-encoded speech emanated from the vox-casters of the Skitarii who had been fighting the Plague Marines. They cautiously peered out from behind the Battle Servitors, trying to understand what had happened.
The Plague Marine's body, a composition of plague, virus, and rotten flesh, was already disintegrating.
The neutron beam had effortlessly burned through the corrupted Mark III Ceramite armour, and the remaining armour plating constrained the resulting disassociation reaction. Energy surged within the armour, leaking out from the seams.
All that was left was a glowing red, empty husk of power armour.
Axion, viewing the scene through the Sentry-Trooper's optics, was surprised. According to his internal data files, neutron weaponry either instantly vaporized a target or caused a massive explosion. This kind of disassociation and ignition effect was unprecedented.
Though he did not understand the specific cause, the weapon was effective and its effects were undeniably intimidating. This was favorable.
However, this intimidating effect was only evident among the Adeptus Mechanicus personnel. It had virtually no effect on the other Plague Marines, Battle Servitors, and Combat Servitors still engaged in the fray. It was fortunate that the Servitors were devoid of emotion and intellect, or the Plague Marines might have annihilated the Skitarii contingent during the moment of hesitation.
Axion watched the Plague Marines, who seemed intent on continuing the fight, with some confusion.
"Do these bio-augmented organisms lack emotion?"
If deterrence was impossible, then total elimination was the obvious course. After all, the Adeptus Mechanicus personnel should be capable of communication, unlike these bio-warriors whose sentience was questionable.
The two Automated Sentry-Troopers quickly demonstrated their powerful firepower and excellent targeting systems. Beam after beam streaked out, and the entire area quickly fell silent.
Apart from the numerous suits of Ceramite armour scattered across the ground in grotesque poses and radiating intense heat, and the soil stained crimson with blood, everything was unnaturally calm. Even the ground, corrupted and blackened by the Plague Marines' presence, ceased its putrefying spread. It was as if a special energy was actively erasing the effects they had brought.
Watching the Adeptus Mechanicus forces attempt to restore order, Axion controlled the two Automated Sentry-Troopers to leap down from the hillside and rapidly approach.
The two automatons that had just effortlessly annihilated nearly ten renegade Space Marines were closing in.
The entire Skitarii force tensed up again.
As the Automated Sentry-Troopers entered the minimum warning perimeter, the Battle Servitors, which had not yet deactivated their combat status, opened fire first.
Heavy bolter rounds fiercely impacted the advancing automatons.
The Sentry-Troopers, moving in a straight line, clearly had not anticipated this reaction. As the bolt shells closed in, their automated evasion systems immediately engaged. Despite their rapid dodging and leaping, they were still struck by several bolt rounds.
However, these powerful weapons, capable of penetrating Ceramite armour, only left a few shallow scratches on the hull of the two Automated Sentry-Troopers. The bolts that successfully detonated only left minor dents and charring on a few specific external points.
During their agile evasive maneuvers, the Sentry-Troopers rapidly activated the grav-autocannons mounted on their other arms.
The familiar thrum-thrum-thrum sound returned, layered over the roar of the bolters.
The bolter fire instantly ceased as several explosions erupted within the Skitarii ranks.
The weaknesses of the Battle Servitors had been fully exposed to Axion during the preceding battle. Their heavy outer alloy armour was even less resistant than Ceramite and offered no defence against the solid projectiles fired by the grav-autocannons. The immense kinetic energy easily ripped apart the bodies of the Servitors.
"Hold fire! All units, cease fire!" Alonas's nervous voice echoed through the ranks.
The remaining Combat Servitors, who had been ready to swarm the enemy, also halted their actions. The tense Skitarii, clutching their frail standard lasguns, warily surrounded the Automated Sentry-Troopers that had just destroyed four Battle Servitors.
Seeing that the other side had ceased attacking, Axion controlled the Sentry-Troopers to abort their counter-attack.
Inside the transport, Morlan, who had witnessed everything via the various flying Servo-skulls, also let out a deep sigh of relief.
"By the Omnissiah's will. They did not continue the assault."